Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
Emdrive Electromagnetic Drive For Chinese Space Ships?
Tired of those conventional space drives that require some sort of reaction mass? Chinese researchers claim to have confirmed the basic principles behind the Emdrive - an electromagnetic drive concept that converts electrical energy into thrust using microwaves.
The Chinese are currently building a demonstration model to see if it works.
('Emdrive' Electromagnetic Space Drive)
Take a look at the explanation offered on Roger Shawyer's Emdrive website:
The principle of operation is based on the well-known phenomenon of radiation pressure. This relies on Newton’s Second Law where force is defined as the rate of change of momentum. Thus an electromagnetic (EM) wave, travelling at the speed of light has a certain momentum which it will transfer to a reflector, resulting in a tiny force.If the same EM wave is travelling at a fraction of the speed of light, the rate of change of momentum, and hence force, is reduced by that fraction. The propagation velocity of an EM wave, and the resulting force it exerts, can be varied depending on the geometry of a waveguide within which it travels. This was demonstrated by work carried out in the 1950’s. (CULLEN, A.L. ‘Absolute Power Measurements at Microwave Frequencies’ IEE Proceedings Vol 99 Part 1V 1952 P.100)
Thus if the EM wave travelling in a tapered waveguide is bounced between two reflectors, with a large velocity difference at the reflector surfaces, the force difference will give a resultant thrust to the waveguide linking the two reflectors. If the reflectors are separated by a multiple of half the effective wavelength of the EM wave, this thrust will be multiplied by the Q of the resulting resonant cavity.
The inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.
The beauty of engineering is that you can actually build something to test it; we'll find out soon enough if Emdrives will power space craft.
In the meantime, you might want to compare the Emdrive explanation with other famous pseudo-scientific science-fictional space drives. See the entries for the spindizzy from James Blish's Cities in Flight and of course the elegant infinite improbability drive from Douglas Adam's Hitchhiker's Guide to the Galaxy .
Via Wired; see also the Emdrive website.
Scroll down for more stories in the same category. (Story submitted 9/29/2008)
Follow this kind of news @Technovelgy.| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 5 )
Related News Stories - (" Space Tech ")
Chrysalis Generation Ship to Alpha Centauri
'This was their world, their planet —
this swift-traveling, yet seemingly moveless vessel.' - Nat Schachner, 1934
The First Space Warship For Space Force
'Each of the electrical ships carried about twenty men...' - Garrett P. Serviss, 1898.
Is China Mining Helium-3 On The Moon's Farside?
'...for months Grantline bores had dug into the cliff.' -
Solitary Black Hole Wanders In Space
'...the Hole is something like a vortex or a whirlpool?' - Frank K. Kelly, 1935.
Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
RoboBallet The Dance Of Cooperative Robots
'...an integrated seven-unit robot team.'
Chrysalis Generation Ship to Alpha Centauri
'This was their world, their planet —
this swift-traveling, yet seemingly moveless vessel.'
Alexa+ And Its AI Brain Improvements
'What's it do?' he asked. 'It amuses.'
Does CloneRobotics Offer A True Android?
Is this What Little Girls Are Made Of?
Brain Implant Is Able To Capture Your Inner Dialogue
'So you see, you can hide nothing from me.'
Are AIs Going Rogue Like Hal 9000
'I know that you and Frank were planning to disconnect me...'
Animated Tumblebugs On Astounding Cover!
'Gaines and Harvey mounted tumblebugs, and kept abreast of the Cadet Captain...'
LingYuan Vehicle Roof Drones Now Available, ala Blade Runner 2049
Accompanied by a small selection of similar ideas from science fiction.
China Steals Strato Airship Design From Google App Engine
'...war-balloons, or, as it would be more correct to call them, navigable aerostats.'
The First Space Warship For Space Force
'Each of the electrical ships carried about twenty men...'
Biohybrid Jellyfish Explore The Ocean
As predicted, and detailed, by science fiction writers!
Should AIs and AI Robots Demand Rights?
'This robot is a creature... It is a manlike being. Therefore, like any other talking, thinking man, he is entitled to a court trial!'
Robot Learns Human Tool Usage By Imitation Learning
'I got one of those new electronic cameras...'
Companion Caregiver ChatGPT Dolls
'Every Artificial Friend is unique, right?'
'Pregnancy Humanoids' From China Replace Moms
'A great many of these synthetic babies were made...'
Man Builds 200 Foot Basement Firing Range
'The basement was huge... carved deep into the rock.'
